PowerOnOff shim not powering up?

Hi,

i have just obtained a button shim and a power onoff shim to use with a pi zero w. I soldered both onto female headers, checked for any shorts in the soldering (none found) and attached the power onoff shim onto the pi zero w board, with the power coming into the micro usb on the on off shim from a fully charged usb powerbank, and an hdmi out connected to a screen (but nothing else connected to the board).

I am not seeing anything much happen. (i think once i saw a red led for second when I was pressing the button). if i connect the powerbank to the pi zero power micro us it comes up perfectly. Ive tried different power supplies as well. What else can I test with? i have a multimeter on hand. I get about 1.8 across where the holes for soldering an external button this drops to zero when the corner button is pressed.

is this an issue with the shim or the power supply (or the operator?) and how can I tell?

thanks for your help

Gareth

Check GPIO Pin 2 for +5V (referenced to ground pin 6) Pressing the on button should send 5V out to the Pi via GPIO pin 2. And remove it again when the Pi shuts down completely.